In her article for the Guardian, Helena Horton reports that unfortunately, the dramatic plant from South America, often seen gracing the grounds of stately homes, has been found to spread rapidly to the detriment of native flora.

The giant Gunnera plants seen in Britain tend to be one of two species, Gunnera manicata or Gunnera tinctoria with the latter being highly invasive. For that reason, since 2017 it has been illegal to plant, cultivate and sell tinctoria. Gunnera Manicata, found to be benign has been widely available.

However as Horton reports, new research conducted by the Royal Horticultural Society (RHS), has revealed that the species on sale appears not to be manicata but an invasive hybrid form (manicata x tinctoria) called Gunnera × cryptica.

Widely planted in gardens across the country, there are significant repercussions from a ban. The law basically means therefore that it would be an offence to plant and cultivate them. It also means that although gardeners are not expected to dig up their prized plants, by caring for them (watering) they could fall foul of the rules.

The RHS has several collections of Gunnera in their gardens, Horton states that some will be removed and “if any plants are retained there will be prominent signage with of the plants and advising gardeners not to plant it in their gardens”.